Tahoe National Forest Sierra Avalanche Center

Pit dug in below treeline terrain on NW aspect micro feature terrain within macro NE aspect terrain.

NTL terrain

Climber's right end crown profile of deep slab avalanche D2.5, R4, that appeared to have been triggered by large cornice fall on Feb 2.

Deep persistent slab avalanche snowboarder triggered mid-slope in below treeline terrain. Failing on NCF's. Partially covered up by additional storm snow, thought to have occurred on Jan 31-Feb 1.

Avalanche occurred in BTL terrain on a shaded E aspect. Snowboarder triggered, 2.5 to 4' crown, 150' wide x 300' long. Relatively small avalanche with potential big consequences from dense trees, rocks, and bed surface about 1' above ground.

This area held very little snow before the Jan 26 storm. The rain crust at 44cm was highly variable in thickness. The facets below that were also highly variable ranging from F hard to 1F+ or P hard across a short distance. I could not find a continuous enough section of the F hard facets for either an Extended Column Test or a Propagation Saw Test.

Snowpit dug in BTL terrain. No signs of the buried surface hoar layer and no weakness found on the near crust facets on the previous rain crust. Very little signs of instabilities found today. 3 day storm HST around 130cm, doubling our previous snowpack.

Tried to do a PST on the Dec 11 facets, but it failed below the rain crust @ 64cm while I was isolating the test. The upper portion of the column did not slide off so I ran a PST on the Dec 11 facets and got PST 40/100 SF @35

Pit dug in below treeline terrain.